Hitherto, a plurality of chip devices such as LED devices are collectively connected with a substrate through a non-conductive adhesive or an anisotropic conductive adhesive by applying heat and pressure with a bonding head. However, there are difference or variation of height of the chip devices and difference or variation of thickness of wirings or height of bumps formed on the chip device or the substrate. Therefore, the heat and pressure applied to each chip device are different. As a result, a chip device not to be heated and pressurized sufficiently or a chip device to be heated and pressurized excessively may be produced. In the former case, connection failure may occur, and in the latter case, the chip device may be damaged.
In order to eliminate the difference or variation of height of the chip devices during the connection operation by the bonding head, it has been proposed to dispose a heat-resistant rubber-like elastic body as a buffer material between the substrate and the bonding head and apply heat and pressure to the chip devices toward the substrate through the heat-resistant rubber-like elastic body.